GB1427275A - Forming extruded tubular metal products - Google Patents

Abstract

1427275 Making tubes; extruding; rolling REVERE COPPER & BRASS Inc 22 Jan 1974 [23 Jan 1973] 03006/74 Headings B3A B3P and B3M A method of forming a tubular product from a preform 10, which includes a body of first material 12 having an aperture (14), Fig. 1 (not shown), in which a deformable mandrel 16 resides, comprises extruding the preform through an extrusion die, annealing the extruded body, and work hardening the annealed body to raise the ultimate tensile strength and yield strength of the body. A titanium alloy billet 12 containing 3% Al and 2À5% V surrounds a mandrel 16, e.g. a carbon steel, which may be bonded thereto by a suitable adhesive lubricant. The conical front end of the preform 10 is engaged with the throat of an extrusion die 24 of a hydrostatic extrusion chamber 20. The titanium alloy extrudant 34 is subsequently annealed at 1300‹ to 1500‹ F. for 1 to 3 hours. The extrudant is then subjected to cold working, e.g. ring rolling by rollers (40), Figs. 3, 4 (not shown). The extruded deformable mandrel 36 is removed by grippers and a non-deformable mandrel 46, e.g. of tool steel, is inserted into the aperture and the extrudant is cold worked to give a 25-50 per cent reduction in area using rotatable shear spinning rollers (50), Figs. 5, 6 (not shown). The non-deformable mandrel is removed and the tubing may be stress-relieved by heating for 1 to 3 hours from 600‹ to 1100‹ F. Alternatively, the tubing can be annealed at a temperature of from 1100‹ to 1700‹ F. for 1 to 3 hours. The lowered yield strength can be raised by an additional shear spinning operation to give a 25 to 50% further reduction in cross-sectional area. The billet 12 may be surrounded with material 60, Fig. 7, to assume a proper volume of hydrostatic fluid 22 for the extrusion.